The present invention relates to platinum group metal catalyzed addition-curable silicone adhesive compositions employing a bis(trialkoxysilylalkyleneoxycarbonylalkylene)amine as an adhesion promoter.
As shown by Schulz U.S. Pat. No. 4,087,585, some self adhering silicone compositions which cure at temperatures of about 150.degree. C., employ an adhesion promoter which is made by mixing a moisture sensitive epoxy containing silane and a hydroxylated vinyl containing polysiloxane under anhydrous conditions. Although many of the adhesion promoters used in addition-curable silicone adhesive compositions do not require special mixing conditions, many of the available adhesion promoters do not provide addition-curable silicone adhesive compositions having a satisfactory degree of adhesion to both metallic and thermoplastic substrates. In determining whether the degree of adhesion on a substrate is satisfactory, the adhesive composition can be applied onto the substrate, such as plastic or metal and thereafter cured. It would be desirable to produce a silicone-substrate composite having a silicone layer which failed cohesively instead of adhesively when tested. As used hereinafter, the expression "adhesive failure" means the silicone layer can be cleanly separated from the substrate, while in a "cohesive failure", rupture occurs in the silicone layer, or in the substrate when separation is achieved.